A. Field of the Invention
This invention relates to an organic adhesive composition for attaching a semiconductor die in a package for the die, which adhesive will withstand high temperatures employed to provide an hermetic seal in the package. It further relates to an improved, low-cost ceramic package for a semiconductor die, which package utilizes the high temperature stable adhesive to mount the semiconductor die in the package. The invention further relates to a novel process for providing the semiconductor device package incorporating the adhesive.
B. Description of the Prior Art
A variety of organic coating and adhesive materials are known for use with semiconductor devices. Such materials are disclosed in, for example, U.S. Pat. Nos. 3,568,012, 3,788,895, and commonly assigned U.S. Pat. No. 3,838,094. While such materials have been proved to be useful in the manufacture of low cost semiconductor device packages for the commercial market, they have generally not proved suitable for use when it is necessary to employ very high temperature sealing processes in subsequent completion of semiconductor device packages. For example, in the present fabrication of ceramic dual-in-line packages for military applications, it is conventional practice to employ a temperature of about 460.degree. C. in the formation of a hermetic seal for the semiconductor die in the package. While progress has been made in increasing the temperature stability of adhesives for semiconductor die, as reported in U.S. Pat. No. 4,233,103, the compositions disclosed there will not provide a shear strength suitable for military specification packages. As a result, military procurement has not qualified any prior art adhesive composition for use.
While the prior art also discloses a wide variety of adhesive formulations for other applications, such as in U.S. Pat. Nos. 3,416,994; 3,073,784; 4,088,801; 3,767,519; 3,726,834; and Russian Pat. No. 405,927, an adhesive composition for use at such elevated temperatures as 460.degree. C. in semiconductor device packages has not been provided in the prior art.